The quaternary structure of polypeptides can greatly influence their physicochemical and biological character. Protein aggregation, or non-native aggregation, refers to the process by which protein molecules assemble into stable complexes composed of two or more proteins, with the individual proteins denoted as the monomer. Aggregates are often held together by strong non-covalent contacts, and require some degree of conformational distortion (unfolding or misfolding) in order to present key stretches of amino acids that form the strong contacts between monomers. While aggregation tends to increase the stability of protein, it often does so at the cost of biological activity of the protein, decreased uniformity of the composition, and can, in some cases, increase the immunogenicity of the protein. These properties adversely affect the ability to use such proteins as a biologic for treatment.